Importance of prey density in relation to the movement patterns of juvenile blacktip sharks (Carcharhinus limbatus) within a coastal nursery area

Abstract

Previous research suggests that nursery areas provide an abundant food source
as well as protection from predation for young sharks, and that these benefits
are the reasons they use these areas. This study examined the abundance of
prey species within a known nursery area, Terra Ceia Bay, Florida, and
compared those data with the amount of time blacktip sharks spent within
various geographic zones within the nursery. The most abundant prey species
within the study site were pinfish, Lagodon rhomboides,
pigfish, Orthopristis chrysoptera, spotfin mojarra,
Eucinostomus argenteus, and silver perch,
Bairdiella chrysoura. Prey species were found to be most
abundant in the mid to southern portion of the nursery area, whereas sharks
spent the majority of their time within the northern portion of the study
site. There was no correlation between the amount of time sharks (as a whole
and by individual) spent within a geographic zone and the abundance of prey
species within that area. These results suggest that prey abundance is not the
main factor directing the movement patterns and habitat choice of juvenile
Carcharhinus limbatus within Terra Ceia Bay. Predator
avoidance may be more important in the use of the nursery grounds by these
young animals than prey abundance.